1. Field of the Invention
This invention relates to a thermoplastic, segmented, linear copolyesterether elastomer. More particularly, the invention concerns such an elastomer having a soft segment formed with a polyether containing tetrahydrofuran and a minor amount of a second ether monomer, such as 3-methyltetrahydrofuran.
2. Description of the Prior Art
A wide variety of thermoplastic, linear polyetheresters have been suggested for various purposes, particularly for the production of molded articles, films and fibers. Such polyetheresters are known, as for example from Witsiepe U.S. Pat. No. 3,766,146, McCormack et al U.S. Pat. No. 4,136,715, Wolfe U.S. Pat. No. 3,775,374, Bell et al U.S. Pat. No. 3,243,413, and Nishimura, et al, "Elastomers Based on Polyester", J. Macromol. Sci. (Chem.), A1(4), 617-625 (1967) among others. However, most of these polyetherester elastomers are not suited for certain specialty applications. For example, elastomeric strands intended for use in elastification of diaper legs or elastomeric fibers intended to be mixed with textile fibers such as nylon for use in heat-set stretch fabrics require a combination of good tensile properties, high elasticity, high melting temperatures and low set. An object of this invention is to provide a thermoplastic elastomer that can be converted into fibers or films suitable for the above-mentioned uses.